Not really. I drink coffee off and on throughout the day, too - but to be fair, I'm making each cup fresh and rarely drink two cups in a row.

Folks react really differently to caffeine. I've never been able to use it to fight against sleepyness, for example. I'm fine drinking it before bed, though I try to give 30 minutes afterwards just so I can pee. I miss drinking coffee if I quit, and tea is hardly a replacement if you are skipping caffeine. (My other beverage is water, and I don't vary often). My father, on the other hand, needed to stop caffeine after lunchtime to sleep well at night. My mother develops headaches, which might not be a problem if it weren't for migraines and cluster headaches. Oddly enough, sometimes the caffeine helps that bit.

Other folks get grouchy if they quit suddenly. A few get hungry, and some folks just feel generally bad.

I drink 3 cups of coffee every day. Often when traveling I'll have occasional periods of 3-5 days without any coffee whatsoever. Don't feel any different.

I drink a cup of coffee every day. If I go a day without it, then I'll get a minor headache around 4pm and then the next day I'll be fine. It heavily depends on the person.